Dial indicator for lathes and the like



Nav. 15, 1949 L; T.'RA1BLE I DIAL INDICATOR FOR LATHES AND THE LIKE Filed May 20, 1944 1N VEN TOR.

LU/S EOMHS RHIBLE.

Patented Nov. 15, 1949 UNITED STATES PATENT OFFICE DIAL INDICATOR FOR LATHES AND THE LIKE Claims.

It has been suggested to operate a dial for indicating the length of travel of a carriage in a lathe, by the use of a pinion engagin the lathe lead screw for purpose of operating the dial. My present invention relates to improvements in such constructions.

One object of my invention is to provide a device in which the dial itself is readily reversible, so that when the lathe carriage is operating by hand traverse, and the lead screw is not used, one dial face can be used, but when the lathe carriage is being driven by the lead screw, as for example in thread cutting, the other dial face can be used, thus providing readily readable calibrations for the type of operation used. In this connection it is my object to provide for a very simple mounting permitting adjustment of the indicating dial to zero, at the start of an operation.

Another object of my invention is to provide for a mounting of the device on the apron of a lathe so that the contact of the operating worm wheel or pinion with the lead screw can be adjusted and preferably so that the worm wheel is resiliently pressed against the lead screw. In this connection my device also provides for lifting the worm wheel entirely out of contact and locking the device in that position.

The above objects and other structural and operative advantages to be noted, I accomplish by that certain construction and arrangement of "parts of which an example will be illustrated and described. The novelty inherent therein will be set forth in the appended claims to which reference is hereby made.

In the drawings:

Figure 1 is a front elevation showing my device with the dial face exposed used where the lead screw is not being rotated during the operation.

Figure 2 is a side elevation of the parts shown in Figure 1, saving the lathe carriage parts.

Figure 3 is an illustration in front elevation showing the other dial face in use, as for thread cutting.

Figure 4 is a section of the dial illustrating also the mode of mounting thereof.

Figure 5 is a detail on line 55 of Figure 1 showing the mounting plate and spring device.

I have illustrated the device as mounted on a j lathe, which may of course, be of an type, and the machine can be of any type having a travelling carriage and a lead screw optionally used for operating the carriage. Thus I indicate a lathe bed at I, a carriage at 2, the rack for use in hand feed at 3, and the lead screw for carriage feed at 4. The dial device is mounted on the .in against the collar H.

apron 5 of the carriage, where it overhangs the bed adjacent to the location of the lead screw.

The device includes a sleeve bearing 6, terminating in a conical shaped mounting base I. These two parts may be in a single casting. A haft 8 is journaled in the sleeve, and has at one end pinned thereto, and bearing against the end of the sleeve, a worm wheel 9. As indicated the wheel is held in place by a pin I0 passing through its collar and through the shaft.

The inner end of the shaft where it projects from the sleeve portion into the mounting base, is provided with a collar H which is finished as a conical bearing for the dial member. The collar prevents endwise movement of the shaft in one direction and with the worm wheel prevents its endwise movement in the other.

The mounting head is dished to receive the dial, which has two frusto-conical faces i2 and 7 l3, and two seats l4 and i5 to engag the conical bearing on the collar l L A ledge It in the dished portion of the mounting head engages and supports the margin of the dial in either of its positions, so that its edge is substantially in the plane of the beveled edge i! of the mounting head.

There is a thumb nut I8 which engages the threaded end E9 of the shaft 8, which head bears on the dial and holds the dial in place on its bear- As so constructed the thumb nut can be removed, and the dial face which it is desired to employ can be turned uppermost, and adjusted to zero indication, whereupon the thumb nut is tightened down. Also loosening the thumb nut will permit adjustment of the dial at the beginning of any operation. The dial face l2 as indicated, is calibrated in micrometer readings as at lZa and the dial face I3 is calibrated in readings suitable for use in cutting threads, as indicated at l3a. A zero mark Ila is formed in the beveled face of the mounting head. The calibrations will also preferably be arranged in direct and reverse, so that feeding in both directions of the table can be indicated and read. This is shown at l2b in Figure 1.

For mounting the device there is attached to or formed as part of the same casting, a sleeve As so constructed, the device when mounted can be located so that th worm wheel bears against the lead screw of the lathe. When the lathe carriage travels along, the lead screw serves as a rack and causes the worm wheel to rotate, and its rotations are communicated to the dial. When the lead screw is operating, tthere a compound effect on the worm wheel caused by the rotation of the shaft and the movement of the carriage, with the result of giving a different movement to'the dial per increment'of movement of the carriage. It is thus desirable to set the face of the dial outermost which serves for the type of operation with or without the lead screw.

The mounting of the device includes th en 'gagement with the threaded end of the shaft '23, "of a hole in the lathe carriage. Thus when the shaft is turned in tightly, the position of the device on the shaft 23 is fixed. When the shaft is turned in loosely, the device can tilt -on the shaft 23. Th spring 'device and stud are so arranged that the spring will press the device to a position tilted to bring the worm wheel into contact with the lead "screw. Thus there is a spring pressed or resilient engagement for "the "drive of the indicator, which automaticall takes up for wear of parts and-does not require a -careful preliminary adjustment.

When it is desired to lock the device out of operation with the head, of the shaft 23 turned away from clamping position, the-device is tilted back out of worm wheel engaging position and the head is then tighteneddown. This looks the gear 9 out of contact position. When in use the head of the shaft 23 is loosened permitting the device to swing to position, held'by' the spring 21, of worm wheel engagement.

It will be evident that the requirements for differently organized machine tools will be different, and that the particular mechanical details of my device, while simple, sturdy and convenient, are not necessary for accomplishment of the novel purpose now illustrated by'an example of my structure.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A dial indicator "for machine tool carriage "travel which comprises a dial, a mounting shaft 'for the dial, means for journalling said shaft, said means including an indexing point for the dial, a gear on the shaft for engagement with the machine tool lead screw, said can having "its opposite faces differently calibrated, and means for removably mountin the dial on the :said mounting shaft so'as' to present the desired face, said dial being frusto-eonical in shape with :its opposed conical-edges calibrated differently, and a dished head mounted on the 'j'ournalimeans which head said dial is seated, and means for 'removably mounting the dial on the mounting shaft.

2. A adial :indicator for machine tool carriage travel which comprises a dial; a mounting shaft for theadial, .means for fjournallingrsaitd shaft, a

gear on the shaft for engagement with th machine tool lead screw, said dial having its opposite faces differently calibrated, and means for removably mounting the dial on the said mounting shaft so as to present the desired face, said dial being frusto-conical in shape with its opposed conical edges calibrated differently, and a dished head mounted on the journal means in "which head said dial seated, the means for removably mounting the dial on the mounting shaft comprising a conical bearing on the shaft, and a double conical seat in the dial where it is *mounted over the shaft, and a thumb nut threaded -'on the end of the shaft and bearing against the dial.

3. A 'dial indicator for machine tool carriage tra-vel which comprises a dial, a mounting shaft for the dial, means for journalling said shaft, a gear on the shaft for engagement with a machine tool lead screw, .and means for mounting the device on the carriage of the machine tool comprising a transverse journal in the journaling means, a shaft therein, said last-named shaft having a threaded-end which-engages :in the'said carriage, and having a head thereon whichabuts the journal whereby the journal can :be clamped to the carriage.

'4. A dial indicator for machine tool carriage travel Which comprises a diaL-a mounting-shaft for the dial, means for ,journalling said shaft, a gear on the shaft for engagement with a machine tool lead screw, and means for mounting the device on the carriage of the machine tool comprising a transverse journal in the journaling means, a shaft therein, said shaft having :a threaded end which engagesrin the said carriage, and having a head thereon whichabuts the-journal whereby the .journal can be clamped to the carriage or rocked on its shaft to adjust thegaosition of the device, and a mounting rplatesecured on the said carriage and :pin andtsl'ot connection between the said journal and the plate, and spring means located .in the slot to bear *on the pin element of said :connection arranged :to :resiliently press the journal toward a position of engagement of the gear with the lead-screw.

5. A dial indicator for .machine tool carriage .travel which comprises a dial, a smom'itingshaft REFERENCES CITED The following references are -of recordin-the file of this patent:

UNITED STATES PATENTS Number Name Date 281,283 Mers'h'on July 1 7, 1883 435,012 Calkins hug-26, T890 997,6'48 Cavanaghet all. -July 1 1, 1911 1,3833% Robbins et a]. July -5, 1921 1,855,700 Wieser Apr. 26, 1932 FQREIGN PATENTS 'Nmnber Country Date France .Aug. .23, 11921 

